Viv, I admire your courage in delving into lib vast--I've been totally intimidated by those records and cannot seem to wrap my mind around what information they provide.
Our marvelous Frances has been studying these for a long time and has contributed some excellent info about the Michael Caine lines.
Check out Orrisdale or Fourtowns info on Manx Note Book www.isle-of-man.com/manxnotebook/gazateer/ml_oryd.htm

The Hugh Caine of Orrisdale was ch 16 Nov 1760 Michael s/o John Caine/Elinor Cannell who md 1757 Michael
The father John died 1764
From Frances' will summaries 1764-2 E w CAINE John dated 18 apr 1764;fourtowns;son hugh(heir land purch robt callister) his dau born this day;wife exex

John had inherited Orrisdale from his father, Patrick Caine (mo Alice Caine) who died in 1758 Michael
From Frances' will summaries 1758
1758-1 E d CAINE Patrick d 24 feb 1758;fourtowns;dau esther caine admr;other ch john + lucy had mar contracts;pledges thos caine ballalheij + wm kelly churchtown;thos caine chosen as guardian;

John and wife Elinor Cannell had M/c son John - dated 8 dec 1757;patk caine orristal + wife alice obo their son john;thos cannel + wife ellinor obo dau ellinor

Hugh Caine/ Mary Kneen
John Caine/Elinor Cannell
Patrick Caine/Alice Caine
Adam Caine/Elinor Stephen (Stoen) I think that Orrisdale passed to the Caines via the Stephen marriage

Hugh died in 1825
From Frances' will summaries 1826 A 33 CAINE Hugh dated 6 oct 1825;ch wm,john,thos,elinor;gson wm corlett;wife mary exex;;1828 thos acks
Full will is online in Brian's index.

DJD